JP7034410B2 - Battery pack with improved safety - Google Patents

Description

The present invention relates to a battery pack with improved safety. More specifically, when the internal temperature of the battery pack rises above a reference value, the user detects an abnormality and shuts off the battery pack from the outside at the same time. Regarding battery packs that are configured to recognize the situation.

This application claims priority based on Korean Patent Application No. 10-2017-0173488 filed on December 15, 2017, and all the contents disclosed in the specification and drawings of the relevant application are incorporated into this application. ..

As the use of portable electrical products such as video cameras, mobile phones, and laptop computers increases, the importance of secondary batteries, which are mainly used as the driving power source for the products, is increasing.

Unlike primary batteries, which are normally not rechargeable, rechargeable and dischargeable secondary batteries are digital cameras, mobile phones, laptop computers, power tools, electric bicycles, electric vehicles, hybrid vehicles, and high-capacity power storage devices. Active research is being conducted in advanced fields such as.

In particular, lithium secondary batteries have a higher energy density per unit weight than other secondary batteries such as conventional lead storage batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries, and can be charged quickly. Because of this, its use is increasing.

A lithium secondary battery has an operating voltage of 3.6 V or higher and is used as a power source for portable electronic devices, or a high-power electric vehicle or hybrid vehicle in which multiple batteries are connected in series or in parallel. Used in power tools, electric bicycles, power storage devices (ESS), UPS, etc.

The use of lithium secondary batteries is increasing rapidly because their operating voltage is three times higher than that of nickel-cadmium batteries and nickel-hydrogen batteries, and their energy density per unit weight is also excellent.

Lithium secondary batteries are classified into lithium ion batteries that use a liquid electrolyte and lithium ion polymer batteries that use a polymer solid electrolyte, depending on the type of electrolyte. Depending on the type of polymer solid electrolyte, the lithium ion polymer battery can be divided into a completely solid lithium ion polymer battery that does not contain an electrolytic solution at all and a lithium ion polymer battery that uses a gel type polymer electrolyte that contains an electrolytic solution. Divided.

In the case of a lithium-ion battery that uses a liquid electrolyte, it is used in a form in which a cylindrical or square metal can is used as a container and welded and sealed. Since the form of a can-type secondary battery using such a metal can as a container is fixed, the design of an electric product using this as a power source is restricted, and it is difficult to reduce the volume. Therefore, a pouch-type secondary battery has been developed and used in which the electrode assembly and the electrolyte are stored in a pouch packaging material manufactured from a film and sealed for use.

However, when a lithium secondary battery is overheated, there is a risk of explosion, so ensuring safety is one of the important issues. Overheating of a lithium secondary battery occurs due to various causes, one of which is when an overcurrent exceeding the limit flows through the lithium secondary battery. When an overcurrent flows, the lithium secondary battery generates heat due to Joule heat, so that the internal temperature of the battery rises rapidly. In addition, a rapid rise in temperature causes a decomposition reaction of the electrolytic solution, causing thermal runaway, which leads to an explosion of the battery. Overcurrent can be caused by a sharp metal object penetrating the lithium secondary battery, shrinkage of the separation film interposed between the positive and negative electrodes, breaking the insulation between the positive and negative electrodes, or external. It occurs when an inrush current is applied to the battery due to an abnormality in the charging circuit or load connected to the battery. In particular, in the case of an electric vehicle, since the battery is mounted under the seat, it is difficult to detect the swelling of the battery cell, which may lead to a fatal accident.

Therefore, a lithium secondary battery is used in combination with a protection circuit to protect the battery from anomalous situations such as the occurrence of overcurrent, which protection circuit is generally charged or charged when an overcurrent occurs. It includes a fuse element that irreversibly disconnects the line through which the discharge current flows.

FIG. 1 is a circuit diagram for explaining the arrangement structure and operation mechanism of the fuse element in the configuration of the protection circuit coupled to the battery pack including the lithium secondary battery.

As shown, the protection circuit monitors the fuse element 1, the sense resistor 2 for overcurrent sensing, and the overcurrent generation to protect the battery pack when an overcurrent occurs, and the fuse element when an overcurrent occurs. It includes a microcontroller 3 for operating 1 and a switch 4 for switching the inflow of operating current to the fuse element 1.

The fuse element 1 is provided on the main line connected to the outermost terminal of the battery pack. The main line is a wiring through which a charging current or a discharging current flows. The drawing shows that the fuse element 1 is provided on the high potential line Pack +.

The fuse element 1 is a three-terminal element component, two terminals are connected to a main line through which a charging or discharging current flows, and one terminal is connected to a switch 4. The inside includes a fuse 1a that is connected in series with the main line and blows at a specific temperature, and a resistance 1b that applies heat to the fuse 1a.

The microcontroller 3 monitors the occurrence of an overcurrent by periodically detecting the voltage across the sense resistor 2, and if it is determined that an overcurrent has occurred, the switch 4 is turned on. Then, the current flowing through the main line is bypassed to the fuse element 1 side and applied to the resistor 1b. As a result, the Joule heat generated by the resistor 1b is conducted to the fuse 1a to raise the temperature of the fuse 1a, and if the temperature of the fuse 1a rises to the blown temperature, the fuse 1a is blown and the main line is irreversible. Is broken. If the main line is disconnected, no more overcurrent will flow, and the problem caused by overcurrent can be solved.

However, the above-mentioned conventional techniques have various problems. That is, if the microcontroller 3 fails, the switch 4 will not be turned on even if an overcurrent occurs. In such a case, the fuse element 1 does not operate because no current flows through the resistance 1b of the fuse element 1. Further, a space for arranging the fuse element 1 is required in the protection circuit, and a program algorithm for controlling the operation of the fuse element 1 must be read into the microcontroller 3. Therefore, there is a disadvantage that the space efficiency of the protection circuit is lowered and the load of the microcontroller 3 is increased.

The present invention has been made in view of the above problems, and the safety in use of the secondary battery is greatly improved by preventing the occurrence of accidents such as ignition without lowering the energy density of the battery cell. It is intended to provide a battery pack configured as such.

However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems will be clearly understood by those skilled in the art by the following description of the invention.

A battery pack according to an aspect of the present invention for solving the above-mentioned technical problems includes at least one battery cell, a pack case accommodating the battery cell and having a penetrating cooling hole, and the pack case. It includes a flow rate measuring device provided on the outside and adjacent to the cooling hole, and an opening / closing unit that opens and closes the cooling hole according to a temperature change inside the pack case.

The flow meter can sense the flow of air flowing from the inside to the outside of the pack case.

The flow meter may issue an alarm when it senses that the air flow is blocked.

The battery pack may be embodied in a form further including an alarm device that issues an alarm when the flow measuring device detects that the flow of air is cut off. That is, the flow rate measuring device has only a function of sensing the flow of air, and a device for issuing an alarm may be separately provided.

The opening / closing unit has a hole lid having a shape and size that matches the cooling hole, a vertical rod connected to the hole lid, and if the temperature inside the pack case rises, the opening / closing unit undergoes morphological deformation due to thermal expansion. It may include one or two bimetals that move the hole lid downward by moving the vertical rod downward and close the cooling hole.

The opening / closing unit warps upward in a convex shape as the temperature rises, and is located in a first bimetal having a through hole through which the vertical rod penetrates and a lower portion of the first bimetal, and is coupled to the vertical rod to obtain a temperature. It can be embodied in a form including a second bimetal that warps downward in a convex shape due to the rise of the first bimetal, and a stopper that is located above the first bimetal and restricts the upward movement of the first bimetal.

The opening / closing unit may be embodied in a form that is located below the second bimetal and further includes an elastic member that elastically supports the second bimetal upward.

The opening / closing unit is coupled to the vertical rod and comprises one bimetal that warps downward as the temperature rises and is located above the one bimetal to limit the upward movement of the one bimetal. Can further include stoppers.

The opening / closing unit extends along the vertical direction of a hole lid having a shape and size matching the cooling hole, a vertical rod having one end connected to the hole lid, and one end thereof being vertical. When the temperature inside the pack case rises with the horizontal rod connected to the other end of the rod, the horizontal rod undergoes morphological deformation due to thermal expansion, and the horizontal rod is moved in a direction away from the vertical rod, thereby causing the vertical. It can be embodied in a form comprising one or two bimetals that move the hole lid connected to the rod downward and close the cooling hole.

The opening / closing unit is positioned adjacent to a first bimetal having a through hole through which the horizontal rod penetrates and a first bimetal that warps convexly in a direction toward the vertical rod due to an increase in temperature, and is located adjacent to the first bimetal. A second bimetal fixed to the other end of the horizontal rod penetrating the above, and a stopper located between the vertical rod and the first bimetal to limit the movement of the first bimetal in the vertical rod direction. It can be embodied in a form including.

The opening / closing unit may be embodied in a form further including an elastic member that elastically supports the second bimetal on the first bimetal side.

The opening / closing unit comprises one bimetal that is coupled to the other end of the horizontal rod and warps convexly in a direction away from the vertical rod as the temperature rises, between the vertical rod and the one bimetal. It may further include a stopper that is located to limit the movement of the one bimetal towards the vertical rod.

According to one embodiment of the present invention, the safety in use of the secondary battery can be ensured by allowing the user to recognize the abnormal sign before the occurrence of an accident such as ignition of the battery pack.

According to another embodiment of the present invention, when the risk of a fire accident inside the battery pack increases, the battery pack is completely shut off from the outside to cut off the supply of oxygen flowing into the inside, and further. Safety can be ensured by preventing the flame from spreading to the outside.

The following drawings, which are attached to the present specification, illustrate desirable embodiments of the present invention and serve to further understand the technical idea of the present invention as well as a detailed description of the present invention. It should not be construed as being limited to the matters described in the drawings.

It is a circuit diagram for demonstrating the arrangement structure and the operation mechanism of a fuse element in the structure of the protection circuit coupled with a battery module. It is a figure which shows the battery pack by one Embodiment of this invention. It is a figure which showed the form which the vertical rod penetrates through the 1st bimetal in the opening / closing unit shown in FIG. It is a figure which showed the state that the cooling hole is closed by the temperature rise in the battery pack by the embodiment shown in FIG. It is a figure which showed the battery pack by another embodiment of this invention. FIG. 5 is a diagram showing how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG. It is a figure which showed the battery pack by still another embodiment of this invention. It is a figure which showed the state that the cooling hole is closed by the temperature rise in the battery pack by the embodiment shown in FIG. 7. It is a figure which showed the battery pack by still another embodiment of this invention. FIG. 9 is a diagram showing how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG.

Hereinafter, desirable embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used herein and in the scope of the claim shall not be construed in a general or lexical sense and the inventor himself shall explain the invention in the best possible way. It must be interpreted in the meaning and concept corresponding to the technical idea of the present invention in accordance with the principle that the concept of terms can be properly defined. Accordingly, the embodiments described herein and the configurations shown in the drawings are merely one of the most desirable embodiments of the invention and do not represent all of the technical ideas of the invention. It must be understood that at the time of filing, there may be a variety of equivalents and variants that can replace them. For example, the vertical rod may or may not penetrate the bimetal.

The structure of the battery pack according to the embodiment of the present invention will be described with reference to FIGS. 2 to 4.

FIG. 2 is a diagram showing a battery pack according to an embodiment of the present invention, and FIG. 3 is a diagram showing a mode in which a vertical rod penetrates a first bimetal in the opening / closing unit shown in FIG. 4 is a diagram showing how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG. 2.

Referring to FIGS. 2 to 4, the battery pack according to the embodiment of the present invention includes at least one battery cell 10, a pack case 20 accommodating the battery cells 10, and a pack case 20 according to a temperature change inside the pack case 20. It is embodied in a form including an opening / closing unit 30 that opens or closes so as to communicate with the outside, and a flow measuring device 40 that senses the outflow of air from the pack case 20.

The number of the battery cells 10 is not limited regardless of the type. One battery cell 10 may be housed in the pack case 20, or two or more battery cells 10 may be housed in the pack case 20 in a state of being electrically connected to each other in series, parallel, or series-parallel. good.

Further, as the number of battery cells 10 housed in the pack case 20 increases, the amount of heat generated in the pack case 20 also increases, so that the need for the opening / closing unit 30 applied to the present invention becomes even greater.

The pack case 20 accommodates at least one battery cell 10, and further includes a space for accommodating an opening / closing unit 30, which will be described later, in addition to the space accommodating the battery cell 10.

The pack case 20 includes at least one cooling hole 20a penetrated therein, and such a cooling hole 20a functions as a passage through which air heated by the heat generated in the battery cell 10 flows out to the outside, whereby the battery is used. The pack can be cooled.

The cooling hole 20a has a shape in which the inlet thereof narrows from the outside to the inside of the pack case 20 so that the hole lid 31 constituting the opening / closing unit 30 described later can be stably coupled to the inner surface of the cooling hole 20a. Can have. If the inlet portion of the cooling hole 20a has a shape that becomes thinner from the outside to the inside, and the hole lid 31 has a shape that matches this as described later, the hole lid 31 has a shape of the cooling hole 20a. The inner surface allows for easier coupling.

On the other hand, a plurality of the cooling holes 20a may be formed. In this case, as many opening / closing units 30 are provided as the number of the cooling holes 20a formed, and all the cooling holes 20a are opened or closed according to the temperature change.

The opening / closing unit 30 is provided at a position corresponding to the position where the cooling hole 20a is formed, and opens / closes the cooling hole 20a according to a temperature change inside the pack case 20. That is, the opening / closing unit 30 operates so as to close the cooling hole 20a when the temperature inside the pack case 20 rises, and operates to open the cooling hole 20a when the temperature inside the pack case 20 falls.

In order to enable such an operation, the opening / closing unit 30 applied to the battery pack according to the embodiment of the present invention includes a hole lid 31, a vertical rod 32, a first bimetal 33, a second bimetal 34, and a stopper 36. In addition, since the second bimetal 34 is fixed to the vertical rod 32, a fixing member 35 such as a bolt may be further included.

The hole lid 31 is located outside the battery pack and has a size and shape that can be matched with the cooling hole 20a as described above. That is, the hole lid 31 may have a substantially inverted trapezoidal shape in which the width of the cross section becomes narrower from the upper part to the lower part.

Such a hole lid 31 closes or opens the cooling hole 20a by the movement of the vertical rod 32 due to the deformation of the bimetals 33 and 34. Since the hole lid 31 has a function of closing and sealing the cooling hole 20a, it can be made of a material such as elastic rubber.

The vertical rod 32 has a long rod shape extending in the vertical direction, one end thereof is connected to the hole lid 31 through a cooling hole 20a, and the other end portion penetrates the first bimetal 33 and is fixed to the second bimetal 34. To. Here, the vertical direction means an up / down direction with reference to FIG. 2.

The bimetals 33 and 34 are formed by joining a pair of metal plates having different thermal expansion rates, respectively, and are located inside the pack case 20, and the temperature rises above the reference value due to the heat generated by the battery cell 10. Then, it warps convexly in the direction of the metal plate having a larger thermal expansion rate.

In the present invention, in the case of the first bimetal 33, the first metal plate 33a having a relatively larger thermal expansion rate is arranged at the upper part, and the second metal plate 33b having a relatively smaller thermal expansion rate is arranged at the lower part. The two metal plates 33a and 33b are in contact with each other and joined to each other. Such a first bimetal 33 undergoes a morphological deformation in which the central portion is convexly warped toward the upper portion, that is, toward the cooling hole 20a side due to the temperature rise inside the pack case 20.

Further, in the case of the second bimetal 34, contrary to the first bimetal 33, the third metal plate 34a having a relatively larger thermal expansion rate is arranged at the lower portion, and the fourth has a relatively smaller thermal expansion rate. The metal plate 34b is arranged at the top, and the two metal plates 34a and 34b are in contact with each other and joined to each other. In such a second bimetal 34, the central portion of the second bimetal 34 warps convexly toward the lower portion, that is, toward the direction away from the cooling hole 20a, contrary to the first bimetal 33, due to the temperature rise inside the pack case 20. Causes morphological deformation.

Since the second bimetal 34 is connected / fixed to the end of the vertical rod 32, the vertical rod 32 moves toward the lower part due to the morphological deformation of the second bimetal 34. Further, the stopper 36 is fixed / arranged between the cooling hole 20a and the first bimetal 33. As a result, when the first bimetal 33 undergoes an upward morphological deformation, it is locked to the stopper 36, and the first bimetal 33 pushes the second bimetal 34 downward due to the reaction.

Therefore, the vertical rod 32 moves downward by a distance that is the sum of the displacements due to the morphological deformations of the first bimetal 33 and the second bimetal 34, thereby connecting / fixing the hole lid 31 to one end of the vertical rod 32. Moves downward to close the cooling hole 20a.

On the other hand, although not shown, an elastic member may be further provided in the lower portion of the vertical rod 32. The elastic member elastically supports the lower portion of the vertical rod 32 so that the vertical rod 32 does not lower when there is no morphological deformation of the bimetals 33 and 34 due to a temperature rise, and the cooling hole 20a is maintained in an open state. can do.

The flow rate measuring device 40 is provided on the outside of the pack case 20 and is arranged adjacent to the inlet of the cooling hole 20a to sense the flow rate of air flowing between the cooling hole 20a and the outside. When the cooling hole 20a is closed due to the morphological deformation of the bimetals 33 and 34 as described above, the flow rate measuring device 40 detects that there is no air flow and directly issues an alarm so that the user can recognize it. It may be configured as such, or an alarm may be issued by transmitting information on the flow rate sensing value to a separately provided alarm device (not shown).

As described above, the battery pack according to the embodiment of the present invention uses the two bimetals 33 and 34 to generate sufficient displacement to quickly and surely close the cooling hole 20a when the temperature inside the battery pack rises. By detecting the change in the flow rate and issuing an alarm, the user can quickly recognize the abnormal temperature rise, and the safety of using the battery pack can be ensured.

Hereinafter, a battery pack according to another embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 is a diagram showing a battery pack according to another embodiment of the present invention, and FIG. 6 is a diagram showing how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG. Is.

The battery pack according to the embodiment shown in FIGS. 5 and 6 is different from the above-described embodiment in that only one bimetal 34 is provided instead of two, and the other components are the above-described implementation. It is substantially the same as the morphology. Therefore, in the battery pack according to the embodiment shown in FIGS. 5 and 6, the description overlapping with the above-described embodiment will be omitted, and the differences will be mainly described.

Referring to FIGS. 5 and 6, in a battery pack according to another embodiment of the present invention, the bimetal 34 is a stopper located above the bimetal 34 and directly or indirectly fixed inside the pack case 20. 36 restricts upward movement.

Further, since the thermal expansion rate of the third metal plate 34a located at the lower portion of the bimetal 34 is larger than that of the fourth metal plate 34b bonded to the upper portion thereof, the central portion of the bimetal 34 is moved downward due to the temperature rise inside the pack case 20. It causes a warped morphological deformation in the form of protruding convexly.

At this time, since the central portion of the bimetal 34 is connected / fixed to the end portion of the vertical rod 32, the vertical rod 32 also moves downward due to the warp of the bimetal 34, thereby connecting / connecting to one end portion of the vertical rod 32. The fixed hole lid 31 moves downward to close the cooling hole 20a.

As described above, since the battery pack according to the other embodiment of the present invention uses only one bimetal, the safety in use of the secondary battery is ensured only by a simple structure as compared with the above-described embodiment. Can be done.

Hereinafter, a battery pack according to still another embodiment of the present invention will be described with reference to FIGS. 7 and 8.

FIG. 7 is a diagram showing a battery pack according to still another embodiment of the present invention, and FIG. 8 shows how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG. 7. It is a figure.

The battery pack according to still another embodiment of the present invention shown in FIGS. 7 and 8 has a horizontal rod 37 and joints 38 and 39 applied as compared with the battery pack according to the embodiments shown in FIGS. 2 to 4. The other components are substantially identical to the embodiments shown in FIGS. 2-4. Therefore, in still another embodiment of the present invention shown in FIGS. 7 and 8, the description overlapping with the above-described embodiment will be omitted, and the differences will be mainly described.

With reference to FIGS. 7 and 8, in a battery pack according to still another embodiment of the present invention, one end of the horizontal rod 37 is fastened to the lower end of the vertical rod 32. At this time, the horizontal rod 37 and the vertical rod 32 may be fastened by a rod joint 38 so as to be relatively rotatable.

On the other hand, the upper end portion of the vertical rod 32 is fastened to the hole lid 31, but at this time, the vertical rod 32 and the hole lid 31 can also be fastened by the lid joint 39 so as to be relatively rotatable.

The horizontal rod 37 is a long rod-shaped part extending along the vertical direction in the extension direction of the vertical rod 32, and is a direction away from the vertical rod 32 due to the shape deformation of the bimetals 33 and 34 due to the temperature rise inside the pack case 20. Move to. In this way, when the horizontal rod 37 moves away from the vertical rod 32, the lower end portion of the vertical rod 32 also moves in the same direction, whereby the hole rotatably connected to the upper end portion of the vertical rod 32. The lid 31 moves downward to close the cooling hole 20a.

As described above, according to still another embodiment of the present invention, by providing the horizontal rod 37 that penetrates the first bimetal 33 and is connected / fixed to the second bimetal 34, the horizontal force is applied in the vertical direction. The cooling hole 20a can be closed by a switching method, whereby the space between the cooling hole 20a and the battery cell 10 can be minimized and the energy density of the battery pack can be increased.

Hereinafter, a battery pack according to still another embodiment of the present invention will be described with reference to FIGS. 9 and 10.

FIG. 9 is a diagram showing a battery pack according to still another embodiment of the present invention, and FIG. 10 shows how the cooling holes are closed due to a temperature rise in the battery pack according to the embodiment shown in FIG. It is a figure.

The battery pack according to the embodiment shown in FIGS. 9 and 10 has a horizontal rod 37 to apply a method of switching the horizontal force in the vertical direction as compared with the embodiment shown in FIGS. 5 and 6. The difference is that the rod joint 38 and the lid joint 39 for smoothly switching the direction of such a force are provided, and the other components are substantially the same. Therefore, in the battery pack according to the embodiment shown in FIGS. 9 and 10, the description overlapping with the above-described embodiment will be omitted, and the differences will be mainly described.

With reference to FIGS. 9 and 10, in a battery pack according to still another embodiment of the present invention, one end of the horizontal rod 37 is fastened to the lower end of the vertical rod 32. At this time, the horizontal rod 37 and the vertical rod 32 may be fastened by a rod joint 38 so as to be able to rotate relative to each other.

On the other hand, the upper end portion of the vertical rod 32 is fastened to the hole lid 31, but at this time, the vertical rod 32 and the hole lid 31 can also be fastened by the lid joint 39 so as to be relatively rotatable.

The horizontal rod 37 is a long rod-shaped part extending along the vertical direction in the extension direction of the vertical rod 32, and moves in a direction away from the vertical rod 32 due to the shape deformation of the bimetal 34 due to the temperature rise inside the pack case 20. do. In this way, when the horizontal rod 37 moves away from the vertical rod 32, the lower end portion of the vertical rod 32 also moves in the same direction, whereby the hole rotatably connected to the upper end portion of the vertical rod 32. The lid 31 moves downward to close the cooling hole 20a.

As described above, according to still another embodiment of the present invention, by providing the horizontal rod 37 connected / fixed to the second bimetal 34, the cooling hole 20a is closed by a method of switching the horizontal force in the vertical direction. This can minimize the space between the cooling holes 20a and the battery cell 10 to increase the energy density of the battery pack.

As described above, the present invention has been described with respect to the limited embodiments and drawings, but the present invention is not limited thereto, and the technique of the present invention is developed by a person having ordinary knowledge in the technical field to which the present invention belongs. It goes without saying that various modifications and modifications are possible within the same range of ideas and claims.

1 Fuse element 1a Fuse 1b Resistance 2 Sense resistance 3 Microcontroller 4 Switch 10 Battery cell 20 Pack case 20a Cooling hole 30 Opening / closing unit 31 Hole lid 32 Vertical rod 33 1st bimetal 33a 1st metal plate 33b 2nd metal plate 34 2nd Bimetal 34a 3rd metal plate 34b 4th metal plate 35 Fixing member 36 Stopper 37 Horizontal rod 38 Rod joint 39 Lid joint 40 Flow measuring instrument

Claims (11)

With at least one battery cell,
A pack case that houses the battery cell and has a penetrating cooling hole,
A flow rate measuring device provided on the outside of the pack case and adjacent to the cooling hole,
A battery pack including an opening / closing unit that opens / closes the cooling hole according to a temperature change inside the pack case .
The opening / closing unit is
A hole lid having a shape and size that matches the cooling hole,
A vertical rod connected to the hole lid and
When the temperature inside the pack case rises to a temperature equal to or higher than the reference temperature, the vertical rod is moved downward to move the hole lid downward and close the cooling hole. Battery pack including two bimetals . The battery pack according to claim 1, wherein the flow rate measuring device senses a flow of air flowing from the inside to the outside of the pack case. The battery pack according to claim 2, wherein the flow rate measuring device issues an alarm when it is detected that the air flow is cut off. The battery pack according to claim 2 or 3, wherein the battery pack further includes an alarm device that issues an alarm when the flow measuring device detects that the air flow is cut off. .. The opening / closing unit is
A first bimetal having a through hole through which the vertical rod penetrates, which warps upward in a convex shape due to a temperature rise.
A second bimetal, which is located below the first bimetal and is coupled to the vertical rod and warps downward as the temperature rises.
The battery pack according to any one of claims 1 to 4 , wherein the battery pack is located above the first bimetal and includes a stopper that restricts the upward movement of the first bimetal. The battery pack according to claim 5 , wherein the opening / closing unit is located below the second bimetal and further includes an elastic member that elastically supports the second bimetal upward. The opening / closing unit comprises one bimetal that is coupled to the vertical rod and warps downward as the temperature rises.
The battery pack according to claim 1 , further comprising a stopper located on top of the one bimetal and restricting the upward movement of the one bimetal. With at least one battery cell,
A pack case that houses the battery cell and has a penetrating cooling hole,
A flow rate measuring device provided on the outside of the pack case and adjacent to the cooling hole,
A battery pack including an opening / closing unit that opens / closes the cooling hole according to a temperature change inside the pack case.
The opening / closing unit is
A hole lid having a shape and size that matches the cooling hole,
A vertical rod whose one end is connected to the hole lid,
A horizontal rod that extends along the vertical direction of the vertical rod and one end of which is connected to the other end of the vertical rod.
When the temperature inside the pack case rises to a temperature equal to or higher than the reference temperature, the horizontal rod is deformed and moved in a direction away from the vertical rod to move the hole lid connected to the vertical rod downward. A battery pack containing one or two bimetals that allow and close the cooling holes. The opening / closing unit is
A first bimetal having a through hole through which the horizontal rod penetrates, which warps convexly in the direction toward the vertical rod due to a temperature rise.
A second bimetal located adjacent to the first bimetal and fixed to the other end of the horizontal rod penetrating the through hole.
The battery pack according to claim 8 , wherein the battery pack is located between the vertical rod and the first bimetal and includes a stopper that limits the movement of the first bimetal in the vertical rod direction. The battery pack according to claim 9 , wherein the opening / closing unit further includes an elastic member that elastically supports the second bimetal on the first bimetal side. The opening / closing unit comprises one bimetal that is coupled to the other end of the horizontal rod and warps convexly in a direction away from the vertical rod as the temperature rises.
One of claims 8 to 10 , further comprising a stopper located between the vertical rod and the one bimetal to limit the movement of the one bimetal in the vertical rod direction. Battery pack as described in section.

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